This invention relates to internal combustion engines and, more particularly, to internal combustion engines including means for minimizing spark plug fouling.
The electrode of spark plugs for an internal combustion engine can be carbonized or fouled when oil or similar materials flows in direct contact therewith. This fouling problem is partilcuarly prevelant in two-cycle engines employing a fuel-lubricant charge and wherein the spark plug is located on the exhaust side of the cylinder. As an uncombusted portion of the fuel-lubricant mixture flows across the cylinder from the intake port to the exhuast port, some of the lubricant and/or other heavy residuals tend to separate from the mixture and collect on the cylinder head, particularly during slow and idling speeds. If the spark plug electrodes extend to the cylinder combustion chamber or otherwise are directly exposed to the combustion chamber, the collected residuals can contact the electrodes and cause fouling and a resultant improper firing within a relatively short period of time.
Representative examples of prior art arrangements for minimizing spark plug fouling are disclosed in French Pat. No. 842,398 and the following United States patents:
Shepherd U.S. Pat. No. 1,552,551--issued Jan. 13, 1925 PA1 Metailler U.S. Pat. No. 2,057,390--issued Oct. 13, 1936 PA1 Warner U.S. Pat. No. 3,710,722--issued July 16, 1973 PA1 Leonard et al U.S. Pat. No. 3,930,471--issued Jan. 6, 1976 PA1 Seufer et al U.S. Pat. No. 3,941,097--issued Mar. 2, 1976